. >> basically have to say it is a hostile environment. >> reporter: in the 2012 season there were 355 ejections. and 14 felony arrests. >> i've been getting quite a few el mails per day -- few e- mails per day saying, my son is going to the game should he wear his jersey. i'm bringing my girlfriend, am i going to be safe. >> reporter: the 49ers have put together a manual addressing their fans how to cheer and dress the part. the goal is to keep fans cool as the competition heats up sunday. >> you don't want to spend the game that you spent a lot of money in one of our patty wagons or substations or jail. >> reporter: the seahawks 12th man fan base is expected to be very visible and very vocal at the stick on sunday. in san francisco, david stevenson, ktvu channel 2 news. >>> and we have a way for you to show your 49er pride. have a little friendly competition going on with our sister station in seattle to see how many people can get likes. share our badge with your facebook friends. if you don't have tickets to the game don't worry about it. you can follow us on the postgame show on f